Responses to noxious stimuli in sedated mechanically ventilated adults

Heart Lung. 2014 Jan-Feb;43(1):6-12. doi: 10.1016/j.hrtlng.2013.10.012. Epub 2013 Oct 25.


Objective: To determine the effect of sedation on physiologic responses and comfort before, during and after a noxious stimulus (endotracheal tube suctioning).

Methods: The sample was a subset of a larger, longitudinal descriptive study, blood for endorphins and saliva for alpha-amylase were obtained before and after suctioning. Heart rate (HR), respiration rate (RR), oxygen saturation (SPO2), and arm and leg actigraphy were continuously recorded.

Results: 67 subjects from medical and surgical ICUs were primarily deeply (37%) or mildly sedated (54%) prior to suctioning. Alpha-amylase increased post suctioning (p = 0.04); endorphins did not change (p = 0.58). Neither were modified by sedation. There were no changes in HR, RR or SPO2 post suctioning. Arm (p = 0.007) and leg actigraphy (p = 0.057) changed from baseline and depended on sedation level (p = 0.0005).

Conclusions: While a stress marker did increase during suctioning, only the measure of patient arm movement was significantly affected by sedation level.

Keywords: Evaluation; Mechanical ventilation; Outcomes; Sedation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Actigraphy
  • Adult
  • Aged
  • Aged, 80 and over
  • Conscious Sedation*
  • Female
  • Heart Rate
  • Humans
  • Intensive Care Units
  • Intubation, Intratracheal / instrumentation
  • Male
  • Middle Aged
  • Movement / physiology
  • Oxygen / blood
  • Respiration, Artificial*
  • Respiratory Rate
  • Saliva / chemistry
  • Suction / adverse effects
  • alpha-Amylases / analysis*
  • beta-Endorphin / blood*


  • beta-Endorphin
  • alpha-Amylases
  • Oxygen